Multipath output control method of flyback switching power supply and flyback switching power supply
By designing a flyback switching power supply with multiple input paths and output windings, combined with a feedback loop and stress absorption unit, the stability and space compactness issues of multiple output voltages in energy storage converters are solved, achieving cost and space savings.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-09
- Publication Date
- 2026-04-17
AI Technical Summary
In modular applications of energy storage converters, flyback switching power supplies struggle to achieve stability and compactness across multiple output voltages, leading to increased equipment costs and space requirements.
The flyback switching power supply design employs multiple input paths and multiple output windings. It generates different voltage levels through the secondary winding of the transformer and uses a feedback loop to regulate the output voltage. Combined with the output modulation circuit and stress absorption unit, it ensures the voltage level requirements and stability.
It achieves stability of multi-output voltage and compact equipment, reduces equipment cost and space occupation, and improves the reliability and anti-interference capability of the control system.
Smart Images
Figure CN121886885A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of switching power supply technology, and in particular to a multi-output control method for a flyback switching power supply, a flyback switching power supply, an energy storage converter, and a computer-readable storage medium. Background Technology
[0002] Generally, flyback switching power supplies need to sample the output voltage as feedback to achieve feedback control and ensure the stability of the output voltage. Therefore, flyback switching power supplies usually only have one or two common-ground outputs.
[0003] With the trend towards modularization of energy storage converters, there are higher requirements for the output of switching power supplies. Due to the output power limitations of flyback switching power supplies and the safety requirements of energy storage converters, most solutions for devices requiring multiple DC power outputs use two or more auxiliary switching power supplies to provide low-voltage isolated power, which not only increases equipment costs but also requires more equipment space, thus causing great inconvenience in use.
[0004] The above content is only used to help understand the technical solution of this application and does not represent an admission that the above content is prior art. Summary of the Invention
[0005] The main objective of this application is to provide a multi-output control method for a flyback switching power supply, a flyback switching power supply, an energy storage converter, and a computer-readable storage medium, with the aim of enabling the flyback switching power supply to provide stable output voltages at various levels.
[0006] To achieve the above objectives, this application provides a multi-output control method for a flyback switching power supply. The flyback switching power supply includes a power input terminal, a startup circuit, a control unit, an input EMI (Electromagnetic Interference Filter), multiple input paths, a transformer, multiple output units, a reference power supply, and a feedback loop. The power input terminal is electrically connected to the power supply terminal of the control unit via the startup circuit, and is also electrically connected to the input terminal of the input EMI. The output terminals of the input EMI are respectively electrically connected to the primary winding side of the transformer via each input path. The secondary winding of the transformer includes an auxiliary winding and multiple output windings. The output terminal of the auxiliary winding is electrically connected to the power supply terminal of the control unit, and the output terminals of each output winding are respectively electrically connected to the input terminals of each output unit. The output terminal of at least one output unit is electrically connected to the data terminal of the control unit via the reference power supply and the feedback circuit. Each input path is equipped with a switching transistor, and each output unit is equipped with an output EMI. Multiple control output terminals of the control unit are respectively electrically connected to the control terminals of the switching transistor and the transformer. The multi-output control method for the flyback switching power supply includes: When the flyback switching power supply is started, the control unit obtains power from the power input terminal based on the startup circuit. The control unit controls the switching transistors in each input path to conduct, so that the input power supply sequentially powers the transformer through the input EMI and each input path, and causes the secondary windings of the transformer to produce voltage outputs of different voltage levels. Each output winding of the control transformer outputs voltage through each output unit, and the control transformer supplies power to the control unit through the auxiliary winding, and stops the control unit from receiving power through the start-up circuit; The control unit obtains the reference voltage provided by the reference power supply and the output voltage of the output unit through the feedback loop. Based on the deviation between the reference voltage and the output voltage, it determines whether the voltage output of each output unit needs to be adjusted so that the output voltage of each channel meets the requirements of the corresponding voltage level.
[0007] Optionally, the output unit further includes an output modulation circuit, which is located between the output EMI and the output terminal of the output unit; the control terminal of the output modulation circuit is also electrically connected to the control output terminal of the control unit; the control unit adjusts the voltage output of the output unit by adjusting the operating parameters of the output modulation circuit.
[0008] Optionally, the input path is also equipped with a corresponding first stress absorption unit for the switching transistor; The output unit further includes a second stress absorption unit, which is located between the input terminal of the output unit and the output EMI.
[0009] Optionally, the feedback loop is also used to isolate the reference voltage and the output voltage of the output unit.
[0010] Optionally, the main control module of the control unit is built based on the UC2844 chip, and the reference power supply is built based on the TL431 chip.
[0011] To achieve the above objectives, this application also provides a flyback switching power supply, which includes a power input terminal, a startup circuit, a control unit, an input EMI, multiple input paths, a transformer, multiple output units, a reference power supply, and a feedback loop. The power input terminal is electrically connected to the power supply terminal of the control unit via the startup circuit, and is also electrically connected to the input terminal of the input EMI. The output terminals of the input EMI are respectively connected to the primary winding side of the transformer via each input path. The secondary winding of the transformer includes an auxiliary winding and multiple output windings. The output terminal of the auxiliary winding is electrically connected to the power supply terminal of the control unit, and the output terminals of each output winding are respectively electrically connected to the input terminals of each output unit. The output terminal of at least one output unit is electrically connected to the data terminal of the control unit via the reference power supply and the feedback circuit. Each input path is equipped with a switching transistor, and each output unit is equipped with an output EMI. Multiple control output terminals of the control unit are respectively electrically connected to the control terminals of the switching transistor and the transformer. The control unit includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the computer program is executed by the processor, it implements the steps of the multi-output control method for the flyback switching power supply described above.
[0012] To achieve the above objectives, this application also provides an energy storage converter, wherein the energy storage converter uses the flyback switching power supply described above as an auxiliary power supply.
[0013] To achieve the above objectives, this application also provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the steps of the multi-output control method for the flyback switching power supply described above.
[0014] This application provides a multi-output control method for a flyback switching power supply, a flyback switching power supply, an energy storage converter, and a computer-readable storage medium. The flyback switching power supply, through a unique circuit design including multiple input paths, multiple output windings, and output units, enables each secondary winding of the transformer to generate voltage outputs of different voltage levels, meeting the multiple voltage requirements of a single device. This eliminates the need for multiple auxiliary switching power supplies, reducing equipment costs and saving internal space, making the equipment more compact. Furthermore, the control unit obtains the reference voltage and the output voltage of the output units through a feedback loop, adjusting the voltage output of each output unit according to the deviation value to ensure that each output voltage meets the corresponding voltage level requirements, guaranteeing the stability of the output voltage. Attached Figure Description
[0015] Figure 1 This is a schematic diagram of the structure of a flyback switching power supply in one embodiment of this application; Figure 2This is a schematic diagram of the steps of a multi-output control method for a flyback switching power supply in one embodiment of this application; Figure 3 This is a schematic diagram of the internal architecture of the control unit of a flyback switching power supply according to an embodiment of this application.
[0016] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation
[0017] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.
[0018] Furthermore, descriptions using terms such as "first" and "second" in this application are for descriptive purposes only (e.g., to distinguish identical or similar features) and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, features defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, technical solutions from different embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If a combination of technical solutions is contradictory or impossible to implement, such a combination should be considered nonexistent and not within the scope of protection claimed in this application.
[0019] In one embodiment, a multi-output control method for a flyback switching power supply is provided, referring to... Figure 1 The flyback switching power supply includes a power input terminal, a startup circuit, a control unit, an input EMI filter, multiple input paths, a transformer, multiple output units, a reference power supply, and a feedback loop. The power input terminal is electrically connected to the power supply terminal of the control unit via the startup circuit, and is also electrically connected to the input terminal of the input EMI filter. The output terminals of the input EMI filter are electrically connected to the primary winding side of the transformer via each input path. The secondary winding of the transformer includes an auxiliary winding and multiple output windings. The output terminal of the auxiliary winding is electrically connected to the power supply terminal of the control unit, and the output terminals of each output winding are electrically connected to the input terminals of each output unit. The output terminal of at least one output unit is electrically connected to the data terminal of the control unit via the reference power supply and the feedback circuit. Each input path contains a switching transistor, and each output unit contains an output EMI filter. Multiple control output terminals of the control unit are electrically connected to the control terminals of the switching transistors and the transformer. Based on the above flyback switching power supply, referring to Figure 2 The multi-output control methods for flyback switching power supplies include: Step S10: When the flyback switching power supply is started, the control unit obtains power from the power input terminal based on the startup circuit; Step S20: The control unit controls the switching transistors in each input path to conduct, so that the input power supply sequentially powers the transformer through the input EMI and each input path, and causes the secondary windings of the transformer to generate voltage outputs of different voltage levels. Step S30: Each output winding of the control transformer outputs voltage through each output unit, and the control transformer supplies power to the control unit through the auxiliary winding, and the control unit stops receiving power through the start-up circuit; Step S40: The control unit obtains the reference voltage provided by the reference power supply through the feedback loop, and obtains the output voltage of the output unit. Based on the deviation between the reference voltage and the output voltage, it determines whether it is necessary to adjust the voltage output of each output unit so that the output voltage of each channel meets the requirements of the corresponding voltage level.
[0020] In this embodiment, the power input terminal is the energy source access point for the entire flyback switching power supply, used to connect to an external power source to provide power to subsequent circuits. The external power source can be DC power after rectification and filtering from AC mains, or other suitable DC power sources. This input terminal introduces electrical energy into the switching power supply system.
[0021] The startup circuit is electrically connected to both the power input terminal and the power supply terminal of the control unit. Its main function is to provide the necessary startup power to the control unit during the initial startup phase of the flyback switching power supply. Once the power is connected, the startup circuit begins to operate, converting the electrical energy at the power input terminal into voltage and current suitable for the control unit's startup, enabling the control unit to begin normal operation and further control the entire switching power supply system.
[0022] The control unit is the core control component of a flyback switching power supply, and it has several important functions and connection ports: (1) Power supply port: When the power supply is started, the power supply terminal obtains electrical energy from the power input terminal through the starting circuit to achieve initial start-up; after the switching power supply is working normally, the power supply terminal is powered by the auxiliary winding of the transformer, at which time the control unit stops obtaining power through the starting circuit.
[0023] (2) Control output terminals: The multiple control output terminals of the control unit are respectively connected to the control terminals of the switching transistors in each input path and the transformer. By outputting appropriate control signals, the control unit can accurately control the on and off times of the switching transistors, thereby adjusting the current and energy input to the primary winding of the transformer; at the same time, it can also control and adjust the operating state of the transformer.
[0024] (3) Data terminal: The data terminal of the control unit is connected to the reference power supply and the output terminal of at least one output unit through a feedback loop. Through the feedback loop, the control unit can obtain the reference voltage provided by the reference power supply and the actual output voltage of the output unit, and determine whether the voltage output of each output unit needs to be adjusted based on the deviation between the two to ensure that the output voltage meets the requirements of the corresponding voltage level.
[0025] The input EMI connector is located between the power input terminal and each input path. Its main function is to suppress electromagnetic interference introduced by the power input terminal, including conducted and radiated interference from external power sources, and also to prevent electromagnetic interference generated by the switching power supply itself from feeding back into the external power supply. Input EMI can improve the electromagnetic compatibility of the power supply, ensuring stable and reliable operation of the switching power supply in complex electromagnetic environments.
[0026] The multiple input paths are used to transmit electrical energy, after input EMI filtering, to the primary winding of the transformer. Each input path has a switching transistor, whose on / off state is controlled by the control output of the control unit. When the switching transistor is on, electrical energy from the input power supply can be transmitted to the primary winding of the transformer through this input path; when the switching transistor is off, the input path is cut off, stopping the power supply to the primary winding of the transformer. By controlling the on and off times of the switching transistors, the energy input to the primary winding of the transformer can be adjusted, thereby affecting the output voltage of the secondary winding of the transformer.
[0027] The transformer is a key component in flyback switching power supplies for voltage conversion and energy transfer, and its primary winding and secondary winding have different functions.
[0028] The primary winding connects to each input path. When the switch in the input path is turned on, the electrical energy of the input power supply is stored in the magnetic field of the primary winding. When the switch is turned off, the energy stored in the primary winding is transferred to the secondary winding through electromagnetic induction.
[0029] The secondary winding includes an auxiliary winding and multiple output windings. The output terminal of the auxiliary winding is connected to the power supply terminal of the control unit, providing a stable operating power supply to the control unit after the switching power supply is working normally. The multiple output windings generate voltage outputs of different voltage levels according to different turns ratios to meet the needs of different loads.
[0030] The multi-output unit corresponds to each output winding of the transformer. The input terminal of each output unit is connected to the corresponding output winding, and the output terminal provides the required voltage and current to the load. Each output unit is equipped with an output EMI, which functions similarly to the input EMI to suppress electromagnetic interference at the output terminal, ensure the stability and purity of the output voltage, and reduce the electromagnetic interference impact on the load equipment.
[0031] In this configuration, the output terminal of at least one output unit is electrically connected to the data terminal of the control unit via a reference power supply and a feedback circuit.
[0032] The reference power supply provides a stable reference voltage for the feedback loop. This reference voltage is a preset standard voltage value used to compare with the actual output voltage of the output unit. The control unit determines whether the output voltage meets the requirements based on the deviation between the two values and takes appropriate adjustment measures.
[0033] The main function of the feedback loop is to draw power from the main circuit and compare it with the reference power supply to form a feedback signal. After isolation through the feedback loop, the signal is sent to the control unit to form a feedback control loop.
[0034] As described in step S10, when the flyback switching power supply starts, the entire system is in its initial state, and the control unit has not yet started working normally. At this time, it is necessary to provide the power required for the control unit to start. This is the function of the startup circuit, which connects the power input terminal and the power supply terminal of the control unit.
[0035] The power input terminal is connected to an external power source. The startup circuit processes the electrical energy at the power input terminal appropriately, such as performing voltage conversion and filtering, to ensure it meets the power requirements of the control unit during startup. After processing by the startup circuit, the electrical energy is delivered to the power supply terminal of the control unit, providing the voltage and current required for startup, enabling the control unit to power on and initialize, entering the working preparation state.
[0036] As described in step S20, after receiving startup power and completing initialization, the control unit begins to perform its control function. The multiple control output terminals of the control unit are respectively connected to the switching transistors in each input path. The control unit sends conduction signals to these switching transistors, causing them to be in the conducting state.
[0037] At this point, the electrical energy from the input power supply begins to flow sequentially through the input EMI and each input path to the primary winding of the transformer. The input EMI plays a crucial role in suppressing electromagnetic interference, filtering out any electromagnetic interference signals that may exist in the input power supply, and preventing interference generated during the operation of the switching power supply from being fed back into the input power supply, thus ensuring the electromagnetic compatibility of the power system.
[0038] When electrical energy enters the primary winding of a transformer, a changing magnetic field is generated in the primary winding according to the principle of electromagnetic induction. Since the secondary winding of the transformer is magnetically coupled to the primary winding, the changing magnetic field induces an electromotive force in the secondary winding. Because the secondary winding includes an auxiliary winding and multiple output windings, and each winding has a different number of turns, according to the transformer's transformation principle U1 / U2=N1 / N2 (where U1 and U2 are the primary and secondary voltages, respectively, and N1 and N2 are the number of turns in the primary and secondary windings, respectively), output windings with different numbers of turns will produce voltage outputs of different levels.
[0039] As described in step S30, after each secondary winding of the transformer generates voltage output, the control unit begins to control each output winding to output voltage through the corresponding output unit. Each output unit is equipped with a corresponding output EMI, which further filters and suppresses interference in the output voltage, ensuring that the voltage output to the load is stable and pure, and reducing the impact of electromagnetic interference on the load equipment.
[0040] Simultaneously, the auxiliary winding of the transformer also generates a corresponding voltage output. The output terminal of the auxiliary winding is connected to the power supply terminal of the control unit, providing a stable operating power supply to the control unit. At this time, the control unit will stop obtaining power through the startup circuit. This is because the startup circuit only needs to provide temporary startup power to the control unit during the power-on phase. After the switching power supply is working normally, the power provided by the auxiliary winding is more stable and suitable, meeting the long-term stable operation requirements of the control unit. The control unit can switch from power supply from the startup circuit to power supply from the auxiliary winding through its internal power management mechanism.
[0041] As described in step S40, during normal operation of the switching power supply, the control unit needs to monitor in real time whether the output voltage of the output unit meets the requirements of the corresponding voltage level. This is achieved through a feedback loop. The feedback loop connects the output terminal of at least one output unit, the reference power supply, and the data terminal of the control unit.
[0042] The reference power supply provides a stable reference voltage to the feedback loop. This reference voltage is a pre-set standard voltage value that represents the ideal voltage that the output unit should output. The control unit obtains the reference voltage provided by the reference power supply through the feedback loop, and also obtains the actual output voltage of the output unit.
[0043] Optionally, the control unit compares the reference voltage with the output voltage and calculates the deviation between them. If the deviation is within the allowable error range, the output voltage meets the requirements, and the control unit does not need to adjust the voltage output of the output unit. If the deviation exceeds the allowable error range, the output voltage deviates from the set voltage level requirement. The control unit will then adjust the on and off times of the switching transistors to change the energy input to the primary winding of the transformer, based on the magnitude and direction of the deviation. For example, if the output voltage is too low, the control unit will increase the on-time of the switching transistors, allowing more electrical energy to be input to the primary winding of the transformer, thereby increasing the output voltage of the secondary winding. If the output voltage is too high, the control unit will decrease the on-time of the switching transistors, reducing the energy input to the primary winding of the transformer, thus reducing the output voltage of the secondary winding. In this way, the control unit continuously adjusts the voltage output of each output unit to ensure that each output voltage always meets the requirements of the corresponding voltage level.
[0044] Optionally, when only one output unit's output terminal is electrically connected to the control unit's data terminal via a reference power supply and feedback circuit, the control unit, after obtaining the deviation between the output voltage of that output unit and the reference voltage and calculating the corresponding voltage regulation value, can combine the set voltage difference between each output unit to obtain the voltage regulation value of the other output units.
[0045] Alternatively, when the output terminals of each output unit are electrically connected to the data terminal of the control unit via a reference power supply and a feedback circuit, the output voltage range of one of the output units can be adapted to the voltage range of the reference power supply. Based on this, combined with the set voltage difference between each output unit, the reference voltage range corresponding to each output unit can be calculated, and then the deviation value between the output unit of each output unit and the corresponding reference voltage can be calculated, thereby enabling feedback control of each output unit.
[0046] In one embodiment, the flyback switching power supply, through its unique circuit design including multiple input paths, multiple output windings, and output units, enables each secondary winding of the transformer to generate voltage outputs of different voltage levels, meeting the multiple voltage requirements of a single device. This eliminates the need for multiple auxiliary switching power supplies, reducing equipment costs and saving internal space, making the device more compact. Furthermore, the control unit obtains the reference voltage and the output voltage of the output units through a feedback loop, and adjusts the voltage output of each output unit according to the deviation value, ensuring that each output voltage meets the corresponding voltage level requirements and guaranteeing the stability of the output voltage.
[0047] This flyback switching power supply can output multiple DC power supplies at different voltage levels and has a very wide input voltage range, operating stably within the 250VDC-1000VDC range. Furthermore, it boasts a high power output, reaching the theoretical upper limit of 250W for flyback switching power supplies, while achieving effective isolation. Different outputs meet standard reinforced insulation requirements, and the overall feedback loop is highly responsive, ensuring extremely stable control even under extreme operating environments. Using this flyback switching power supply as the auxiliary power supply for the energy storage converter can reduce the space occupied by the equipment. At the same time, the flyback switching power supply adopts a dual-tube flyback design, which greatly reduces the specifications of the components on the primary side of the transformer. The extremely high stability increases the reliability of the control circuit of the energy storage converter. The simple design effectively reduces the size and cost of the auxiliary power supply section in the energy storage converter.
[0048] In one embodiment, based on the above embodiment, the output unit further includes an output modulation circuit, which is located between the output EMI and the output terminal of the output unit; the control terminal of the output modulation circuit is also electrically connected to the control output terminal of the control unit; the control unit adjusts the voltage output of the output unit by adjusting the operating parameters of the output modulation circuit.
[0049] In this embodiment, each output unit, in addition to containing an output EMI, also includes an output modulation circuit. This output modulation circuit is positioned between the output EMI and the output terminal of the output unit. Specifically, the voltage signal output from the output winding of the transformer secondary side first undergoes electromagnetic interference filtering and suppression through the output EMI before entering the output modulation circuit. The control terminal of the output modulation circuit is electrically connected to the control output terminal of the control unit, meaning that the control unit can send control signals to the output modulation circuit to regulate its operating state.
[0050] The main function of the output modulation circuit is to further adjust and optimize the voltage signal after output EMI processing, ensuring that the output voltage of the output unit can more accurately meet the requirements of the corresponding voltage level. By changing its own operating parameters, the output modulation circuit can adjust the voltage amplitude, frequency, duty cycle, and other characteristics, thereby achieving effective control of the output voltage.
[0051] The control unit plays a crucial role in the entire operation of the flyback switching power supply. After acquiring the reference voltage provided by the reference power supply and the actual output voltage of the output unit, the control unit calculates the deviation between the two. Based on this deviation, the control unit determines whether the voltage output of the output unit needs to be adjusted.
[0052] When the output voltage needs to be adjusted, the control unit sends corresponding control signals to the output modulation circuit through its control output terminal. The specific form and parameters of these control signals depend on the control algorithm of the control unit and the operating principle of the output modulation circuit. For example, if the output modulation circuit operates based on pulse width modulation (PWM) technology, the control unit may adjust the operating parameters of the output modulation circuit by changing the duty cycle of the PWM signal.
[0053] The following uses a pulse width modulation output modulation circuit as an example to explain in detail the process of the control unit adjusting the output unit voltage output: (1) The control unit obtains the reference voltage V1 provided by the reference power supply and the actual output voltage V2 of the output unit through the feedback loop, and calculates the deviation value ΔV=V1-V2 between the two.
[0054] (2) The control unit generates a corresponding control signal based on the deviation value ΔV. If ΔV>0, it means that the actual output voltage is lower than the reference voltage, and the control unit needs to increase the output voltage of the output modulation circuit; conversely, if ΔV<0, the output voltage of the output modulation circuit needs to be reduced.
[0055] (3) The control unit will adjust the duty cycle of the PWM signal according to the calculated deviation value. For example, if it is necessary to increase the output voltage, the control unit will increase the duty cycle of the PWM signal, so that the conduction time of the switching transistor in the output modulation circuit is longer, thereby increasing the output voltage; conversely, if it is necessary to decrease the output voltage, the control unit will decrease the duty cycle of the PWM signal and shorten the conduction time of the switching transistor.
[0056] (4) After adjusting the operating parameters of the output modulation circuit, the control unit will continue to monitor the actual output voltage of the output unit through the feedback loop. If the actual output voltage still deviates from the reference voltage, the control unit will repeat the above steps and continuously adjust the operating parameters of the output modulation circuit until the output voltage meets the requirements of the corresponding voltage level.
[0057] In one embodiment, by adding an output modulation circuit to the output unit and having its operating parameters adjusted by the control unit, more precise and flexible control of the output unit's voltage output can be achieved. This approach can effectively improve the output voltage accuracy and stability of the flyback switching power supply, reduce output voltage deviations caused by load changes, input voltage fluctuations, and other factors, thereby better meeting the voltage requirements of different loads. Simultaneously, the introduction of the output modulation circuit can also enhance the flyback switching power supply's anti-interference capability, improving the reliability and performance of the entire power supply system.
[0058] Because of the large number of output windings and the wide range of input voltage, control is difficult at high and low voltage. Therefore, an output modulation circuit needs to be added to the output section to give the feedback loop a larger feedback current and enhance the reliability of the control system.
[0059] In one embodiment, based on the above embodiment, the input path is further provided with a corresponding first stress absorption unit for the switching transistor; The output unit further includes a second stress absorption unit, which is located between the input terminal of the output unit and the output EMI.
[0060] In this embodiment, in the input path of the flyback switching power supply, the switching transistor experiences significant voltage and current stress during turn-on and turn-off. When the switching transistor turns off rapidly, the current in the primary winding of the transformer is suddenly interrupted. Due to the characteristics of the inductance, a reverse voltage spike is generated. This voltage spike may far exceed the withstand voltage of the switching transistor, thereby damaging it. The main function of the first stress absorption unit is to absorb this voltage spike, protecting the switching transistor from excessive voltage surges and improving its reliability and lifespan.
[0061] Optionally, the first stress-absorbing unit can be an RCD absorption circuit composed of resistors, capacitors, and diodes. Its working principle is as follows: (1) Switch conduction stage: At this time, the diode is in the off state, and the capacitor slowly discharges through the resistor to prepare for the next absorption of the peak voltage.
[0062] (2) Switch-off stage: The reverse spike voltage generated by the primary winding of the transformer causes the diode to conduct. The spike voltage charges the capacitor through the diode, storing the spike energy in the capacitor. At the same time, the resistor consumes some energy to prevent the capacitor voltage from becoming too high. Over time, the capacitor slowly discharges through the resistor, consuming the stored energy.
[0063] In the output unit of a flyback switching power supply, voltage and current spikes are generated when the current in the secondary winding of the transformer changes. These spikes can damage the output EMI filter and subsequent loads, affecting the stability and output quality of the power supply. The function of the second stress absorption unit is to absorb these voltage and current spikes, protecting the output EMI filter and load, while reducing electromagnetic interference and improving the electromagnetic compatibility of the power supply.
[0064] Optionally, the second stress-absorbing unit can also employ an RCD absorption circuit, the principle of which is similar to that of the first stress-absorbing unit. Alternatively, other forms of absorption circuits can be used, such as an LC absorption circuit. An LC absorption circuit consists of an inductor and a capacitor, utilizing their resonant characteristics to absorb peak energy. When a voltage spike occurs, the inductor limits the rate of change of current, while the capacitor stores and releases energy, thus achieving the purpose of absorbing the spike.
[0065] In one embodiment, the first stress absorption unit protects the switching transistor, and the second stress absorption unit protects the output EMI filter and the load, thereby improving the overall reliability of the flyback switching power supply and reducing the probability of failure. The stress absorption unit absorbs peak voltage and current, reducing the generation of electromagnetic interference and making the power supply more likely to meet relevant electromagnetic compatibility standards. By reducing the peak voltage and current of the output unit, the second stress absorption unit can improve the output stability and quality of the power supply, providing a cleaner power supply to the load.
[0066] In summary, configuring a first stress absorption unit and a second stress absorption unit in the input path and output unit of a flyback switching power supply, respectively, can effectively improve the performance and reliability of the power supply.
[0067] In one embodiment, based on the above embodiment, the feedback loop is further used to isolate the reference voltage and the output voltage of the output unit.
[0068] In this embodiment, the specific method for achieving isolation of the feedback loop can be optical isolation.
[0069] An optocoupler is a device that uses light as a medium to transmit electrical signals. It consists of a light source and a light receiver. In the feedback loop, the reference voltage and the output voltage of the output unit are converted into optical signals for transmission. Then, at the receiving end, the optical signals are converted back into electrical signals. Because the transmission of optical signals is not affected by electromagnetic interference, electrical isolation can be effectively achieved.
[0070] In the feedback loop, the reference voltage and the output voltage of the output unit are connected to the input terminals of the LEDs of the optocoupler. When a voltage is input, the LEDs emit light, and the optical signal is received by the photodetector inside the optocoupler and converted into an electrical signal. The electrical signal output by the photodetector is then transmitted to the data terminal of the control unit. In this way, the reference voltage and the output voltage of the output unit are electrically isolated during transmission, avoiding mutual interference.
[0071] By isolating the reference voltage and the output voltage of the output unit through a feedback loop, the influence of interference signals can be effectively eliminated, making the reference voltage and output voltage information obtained by the control unit more accurate. This allows the control unit to more precisely determine the deviation between the reference voltage and the output voltage, thereby more accurately adjusting the voltage output of each output unit.
[0072] The isolated voltage signal is more stable, reducing the possibility of control unit misjudgments due to interference and improving the overall stability of the flyback switching power supply. Even in complex electromagnetic environments, the power supply can operate reliably, ensuring that the output voltages of each circuit meet the requirements of their respective voltage levels.
[0073] Isolation also prevents high voltage or abnormal voltage from the output unit from damaging the control unit. When the output unit experiences abnormal conditions such as overvoltage or overcurrent, isolation measures can separate these abnormal signals from the control unit, protecting the control unit's safety.
[0074] In one embodiment, based on the above embodiments, the main control module of the control unit is built on the UC2844 chip, and the reference power supply is built on the TL431 chip.
[0075] In this embodiment, a UC2844+TL431 scheme is used to transform the input high-voltage power supply into a stable low-voltage isolated power supply. The core idea is to use the UC2844 to control the primary-side switching transistor to achieve PWM control, and the TL431 to provide a precise voltage reference and error amplification on the secondary side. An optocoupler is used to achieve isolation feedback between the primary and secondary sides. Through the negative feedback loop formed by the TL431 and the optocoupler, the system automatically adjusts the on-time of the switching transistor to stabilize the output voltage.
[0076] Furthermore, this application embodiment also provides a flyback switching power supply, which includes a power input terminal, a startup circuit, a control unit, an input EMI, multiple input paths, a transformer, multiple output units, a reference power supply, and a feedback loop; wherein, the power input terminal is electrically connected to the power supply terminal of the control unit via the startup circuit, and the power input terminal is also electrically connected to the input terminal of the input EMI; the output terminal of the input EMI is electrically connected to the primary winding side of the transformer via each input path; the secondary winding of the transformer includes an auxiliary winding and multiple output windings, the output terminal of the auxiliary winding is electrically connected to the power supply terminal of the control unit, the output terminal of each output winding is electrically connected to the input terminal of each output unit, and the output terminal of at least one output unit is electrically connected to the data terminal of the control unit via the reference power supply and the feedback circuit; each input path is provided with a switching transistor, and each output unit is provided with an output EMI; multiple control output terminals of the control unit are electrically connected to the control terminals of the switching transistor and the transformer; The internal architecture of the control unit can be as follows: Figure 3As shown, the system includes a processor, memory, communication interface, and input interface connected via a system bus. The processor provides computing and control capabilities. The memory includes a non-volatile storage medium and internal memory. The non-volatile storage medium stores the operating system, computer programs, and a database. The internal memory provides an environment for the operation of the operating system and computer programs in the non-volatile storage medium. The database stores data called by the computer programs. The communication interface is used for data communication with external terminals. The input interface is used to receive signals input from external devices. When the computer program is executed by the processor, it implements a multi-output control method for a flyback switching power supply as described in the above embodiment.
[0077] Those skilled in the art will understand that Figure 3 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the flyback switching power supply to which the present application is applied.
[0078] Furthermore, this application embodiment also provides an energy storage converter, which uses the flyback switching power supply described above as an auxiliary power supply. The specific structure of the flyback switching power supply is the same as described in the above embodiments. Since this energy storage converter adopts all the technical solutions of all the above embodiments, it has at least all the technical effects brought about by the technical solutions of the above embodiments, and will not be described in detail here.
[0079] Furthermore, this application also proposes a computer-readable storage medium comprising a computer program that, when executed by a processor, implements the steps of the multiple-output control method for a flyback switching power supply as described in the above embodiments. It is understood that the computer-readable storage medium in this embodiment can be a volatile readable storage medium or a non-volatile readable storage medium.
[0080] In summary, the flyback switching power supply, energy storage converter, and computer-readable storage medium provided in this application embodiment offer a multi-output control method for a flyback switching power supply. The flyback switching power supply, through its unique circuit design including multiple input paths, multiple output windings, and output units, enables each secondary winding of the transformer to generate voltage outputs of different voltage levels, meeting the multiple voltage requirements of a single device. This eliminates the need for multiple auxiliary switching power supplies, reducing equipment costs and saving internal space, making the device more compact. Furthermore, the control unit obtains the reference voltage and the output voltage of the output units through a feedback loop, adjusting the voltage output of each output unit based on the deviation value to ensure that each output voltage meets the corresponding voltage level requirements, thus guaranteeing the stability of the output voltage.
[0081] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium. When executed, the computer program can include the processes of the embodiments of the above methods. Any references to memory, storage, databases, or other media provided in this application and in the embodiments may include non-volatile and / or volatile memory. Non-volatile memory may include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memory may include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in a variety of forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), dual-speed SDRAM (SSRSDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), RAMbus direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM).
[0082] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, apparatus, article, or method that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, apparatus, article, or method. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, apparatus, article, or method that includes that element.
[0083] The above description is only a preferred embodiment of this application and does not limit the patent scope of this application. Any equivalent structural or procedural transformations made based on the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.
Claims
1. A multi-output control method for a flyback switching power supply, characterized in that, The flyback switching power supply includes a power input terminal, a startup circuit, a control unit, an input EMI filter, multiple input paths, a transformer, multiple output units, a reference power supply, and a feedback loop. The power input terminal is electrically connected to the power supply terminal of the control unit via the startup circuit, and is also electrically connected to the input terminal of the input EMI filter. The output terminals of the input EMI filter are electrically connected to the primary winding side of the transformer via each input path. The secondary winding of the transformer includes an auxiliary winding and multiple output windings. The output terminal of the auxiliary winding is electrically connected to the power supply terminal of the control unit, and the output terminals of each output winding are electrically connected to the input terminals of each output unit. The output terminal of at least one output unit is electrically connected to the data terminal of the control unit via the reference power supply and the feedback circuit. Each input path contains a switching transistor, and each output unit contains an output EMI filter. Multiple control output terminals of the control unit are electrically connected to the control terminals of the switching transistors and the transformer. The multi-output control method for the flyback switching power supply includes: When the flyback switching power supply is started, the control unit obtains power from the power input terminal based on the startup circuit. The control unit controls the switching transistors in each input path to conduct, so that the input power supply sequentially powers the transformer through the input EMI and each input path, and causes the secondary windings of the transformer to produce voltage outputs of different voltage levels. Each output winding of the control transformer outputs voltage through each output unit, and the control transformer supplies power to the control unit through the auxiliary winding, and stops the control unit from receiving power through the start-up circuit; The control unit obtains the reference voltage provided by the reference power supply and the output voltage of the output unit through the feedback loop. Based on the deviation between the reference voltage and the output voltage, it determines whether the voltage output of each output unit needs to be adjusted so that the output voltage of each channel meets the requirements of the corresponding voltage level.
2. The multi-output control method for a flyback switching power supply as described in claim 1, characterized in that, The output unit further includes an output modulation circuit, which is located between the output EMI and the output terminal of the output unit; the control terminal of the output modulation circuit is also electrically connected to the control output terminal of the control unit; the control unit adjusts the voltage output of the output unit by adjusting the operating parameters of the output modulation circuit.
3. The multi-output control method for a flyback switching power supply as described in claim 1, characterized in that, The input path also includes a corresponding first stress absorption unit for the switching transistor; The output unit further includes a second stress absorption unit, which is located between the input terminal of the output unit and the output EMI.
4. The multi-output control method for a flyback switching power supply as described in claim 1, characterized in that, The feedback loop is also used to isolate the reference voltage and the output voltage of the output unit.
5. The multi-output control method for a flyback switching power supply as described in claim 1, characterized in that, The main control module of the control unit is built based on the UC2844 chip, and the reference power supply is built based on the TL431 chip.
6. A flyback switching power supply, characterized in that, The flyback switching power supply includes a power input terminal, a startup circuit, a control unit, an input EMI filter, multiple input paths, a transformer, multiple output units, a reference power supply, and a feedback loop. The power input terminal is electrically connected to the power supply terminal of the control unit via the startup circuit, and is also electrically connected to the input terminal of the input EMI filter. The output terminals of the input EMI filter are electrically connected to the primary winding side of the transformer via each input path. The secondary winding of the transformer includes an auxiliary winding and multiple output windings. The output terminal of the auxiliary winding is electrically connected to the power supply terminal of the control unit, and the output terminals of each output winding are electrically connected to the input terminals of each output unit. The output terminal of at least one output unit is electrically connected to the data terminal of the control unit via the reference power supply and the feedback circuit. Each input path contains a switching transistor, and each output unit contains an output EMI filter. Multiple control output terminals of the control unit are electrically connected to the control terminals of the switching transistors and the transformer. The control unit includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When executed by the processor, the computer program implements the steps of the multi-output control method for a flyback switching power supply as described in any one of claims 1 to 5.
7. An energy storage converter, characterized in that, The energy storage converter uses the flyback switching power supply as described in claim 6 as an auxiliary power supply.
8. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by a processor, implements the steps of the multi-output control method for a flyback switching power supply as described in any one of claims 1 to 5.